How much gear rattle is normal for a NV5600

[S.Morris]

Been meaning to ask this question for a while... ... . I have a 6spd that seems to work fine but does have a pronounced rattle under the following circumstances.



If idling in first gear (no fuel) the transmission rattles pretty goood unless rpm is increased up to 1000 or so. Much worse if ground is slightly soft. I have always assumed this was normal for this transmission. (Circumstance I speak of ... . trying to sneak out of a campground as quietly as possible early in the morning)



I know this is common of a big rig transmission but realized I have never heard another NV5600. I am assuming it is normal, but would like to hear a couple of reports from other 5600 owners.



Thanks

Steve

 

[alford]

hope its normal, mine does the same thing, sounds like its coming apart at low rpm on soft ground

 

[macdaddy]

Normal gear lash!!!!!!.



Mac

 

[Diesel Thunder]

Mine has a little clatter as well if at idle in first or reverse. It did quiet down a little when I began overfilling it through the top PTO cover bolt. With the FastCoolers I've got over 7 qts inside. It has been shifting smooth as silk. I've got right at 70K on the truck and even though it has clattered since new, I've never had any problems with it except for some slight "notchiness" when very cold outside.

Good Luck!

 

[HOBrian]

I had the same noise before I installed my AD 100. Now the gear noise is completely gone Everything is same always pull out of the garage and out the driveway in 1st always made the noise!!! AD 100 no more noise.

 

[RVTRKN]

I had the same noise before I installed my AD 100. Now the gear noise is completely gone Everything is same always pull out of the garage and out the driveway in 1st always made the noise!!! AD 100 no more noise.

What is AD100, and mine has done since day one, its normal.

 

[MustangDiesel004]

I have an 04 and had an 01 w/5600 and both rattle. I was told by a Dodge service tech it was the clutch rattling. Also heard a few Fords doin too. I put 120000 on the 01 and 107000 on the 04 so far and havent had any problems.

 

[HOBrian]

What is AD100, and mine has done since day one, its normal.

AirDog 100 fuel system (lift Pump)



I thought it was very weird when I drove out of the garage the first time after install and had no noise.

 

[S.Morris]

Thanks for the replys guys.



I was pretty sure it was normal as is common on the bigger road trucks. Much of their noise is from clutch rattle... .



At least it is not on its way out... . Truck has 175000miles and I bought it about 10K ago. Just wanted to verify.



FYI. . I just did a diff oil change (according to records it was done at 70K with redline oils). Backlash was as new and wear negligable. Oil was only slightly darker and magnet was 90% clean.



Steve

 

[steved]

Its called "critical power moment"... normal for a trans like this.



There is a TSB for clutch rattle in the 03s, mine suffered this... some thing about the clutch disc. It will sound like a can of marbles in nuetral that goes away when the pedal is depressed...

 

[HBarlow]

All of them do it. The power stroke (no reference to Furds intended) of each cylinder in turn applied to the transmission causes the transmission gears to rattle due to ordinary gear lash. My '01 rattled real bad if I slowed down to a very low rpm in third gear and then accelerated gently until the rpms got up a bit. It seemed to get a little worse with miles but the transmission held up well until the large bearing became worn and noisy at around 302k miles. The transmission was rebuilt by Standard Transmission in Ft. Worth, TX and still works great several years later.

 

[fkovalski]

Sounds are hard to describe in words...



Describe the noise more for me... is it more "rattle" (harder, tinny- er) or does it sound like marbles inside the case?



I have the latter... hope it too is normal.

 

[HBarlow]

The rattle I am describing occured in all Cummins-powered Rams w/NV-5600 transmissions I've ever heard run if the driver slowed down to a very low rpm, approximately 1200rpm or so, in gear, like turning a city street corner, then accelerated gently. The power pulses of the mighty Cummins at low rpm would rattle the slack betwen the drive and driven gears for a second or two as the engine gained rpm.

I think the NVH (noise, vibration, harshness) engineers were concerned about this irritating but not harmful shudder/rattle which is probably one of the reasons the newer G-56 equipped trucks now use a dual mass flywheel assembly which dampens out the rattle.

 

[fkovalski]

The rattle I am describing occured in all Cummins-powered Rams w/NV-5600 transmissions I've ever heard run if the driver slowed down to a very low rpm, approximately 1200rpm or so, in gear, like turning a city street corner, then accelerated gently. The power pulses of the mighty Cummins at low rpm would rattle the slack betwen the drive and driven gears for a second or two as the engine gained rpm...

I think you are describing what I sense in mine to be a lot of play in the drivetrian as a whole rather than a rattle. I asked about this at my dealer and they said is was normal... all of the tolerances of all the component added up to give the sensation of "slop" when driving at slow speeds. Another observation I find is that it "seems" to be more prevalent when my truck is unloaded; there appears to be less play when my camper is on.

I think the NVH (noise, vibration, harshness) engineers were concerned about this irritating but not harmful shudder/rattle which is probably one of the reasons the newer G-56 equipped trucks now use a dual mass flywheel assembly which dampens out the rattle.

I big (smoother) difference on the G-56!